1. Field of the Invention
The present invention pertains to toothbrushes, and, in particular, to a toothbrush, such as a power toothbrush, structured to detect brushing angle and provide feedback to the user based on brushing force detected at a plurality of angles.
2. Description of the Related Art
In general, power toothbrushes for cleaning teeth, including removal of plaque, are well known. Typically, power toothbrushes rely on a set of bristles which are attached to a bristle mounting plate, which in turn is moved by a driver mechanism to scrub the surfaces of teeth. Such toothbrushes, which rely on scrubbing action of the bristles for actual cleaning, typically require some amount of force to be exerted by the user against the teeth to accommodate differences in the various shapes and spacing of the teeth and to effectively clean the teeth.
Correct positioning of the bristles of a toothbrush relative to the teeth is essential for efficient plaque removal. To best remove plaque from the teeth, it is often advantageous to brush with the bristles positioned at an angle fairly perpendicular to the tooth. Trials have revealed that users regularly brush their teeth at angle far from the perpendicular. Angles of up to 70 degrees from the perpendicular are common, especially when brushing the inside of the teeth. At such extreme angles, many of the bristles are no longer in contact with the teeth (or are at an inefficient angle) and brushing is extremely inefficient.